955 Battle of Lechfeld: Otto I, Holy Roman Emperor defeated the Magyars (Hungarians), ending 50 years of Magyar invasion of the West.
991 Battle of Maldon: the English, led by Byrhtnoth, Ealdorman of Essex, were defeated by a band of inland-raiding Vikings near Maldon in Essex.
1316 The Second Battle of Athenry during the Bruce campaign in Ireland. The Second Battle of Athenry marked the definitive end of the power of the Ua Conchobair (O'Connor's) as Kings of Connacht. The decades following marked the high point of Norman rule in Connacht, and the rise of the towns of Athenry and Galway as centers of economic and political power and wealth. Unlike the First Battle of Athenry in 1249, no account is given of the battle itself in any surviving account, and even the site of the battle itself is uncertain.